Engineering Research Equipment Grant: Scanning Acoustic Microscope

这项工程研究设备提案是为扫描声学显微镜提供资金，用于在材料工程、精密加工、物理、考古、纤维和聚合物科学等领域进行广泛的研究。真正的声学显微镜是最近发展起来的，现在它的分辨率与光学显微镜相当。光学显微镜和声学显微镜的重要区别在于引起图像对比的原因。光学显微镜中的对比是由于光学折射率和光学吸收系数的存在和变化。一般来说，这些基本参数与材料的物理性质仅间接相关；然而，使用声学显微镜，图像内的对比度是由于弹性，粘弹性和密度特性的变化。因此，图像不依赖于可见光传输。声学显微镜将用于的具体问题有：(1)检查流动诱导取向和高速卷取产生的超取向纤维的微观弹性和粘弹性模量和密度变化；(2)采用非破坏性方法检查界面区域，以减少环氧树脂/石墨纤维复合材料的吸湿性；(3)表征半导体材料中的缺陷，开发新的图像分析技术；(4)研究聚合物基复合材料应变过程中的界面（这是由于复合材料对光不透明但对超声波仍然透明）；(5)协助我校新成立的精密工程中心进行亚表面损伤表征；(6)对考古标本中的地下结构进行检查、计数和测量。

This Engineering Research Equipment proposal is for funds for a scanning acoustic microscope to conduct a broad range of studies in materials engineering, precision machining, physics, archaeometry, and fiber and polymer science. True acoustic microscopes are recent developments that now have a resolution equal to that of a light microscope. The important difference between light- and acoustic- microscopy is in the causes of image contrast. Contrast in light microscopy is due to the existence of and variations in optical indices of refraction and coefficients of optical absorption. These basic parameters are, in general, only indirectly related to the material's physical properties; whereas, with the acoustic microscope, contrast within the image is due to variation in the elastic, viscoelastic and density properties. The image is thus not dependent on visible light transmission. Specific problems on which the acoustic microscopy is to be used are: (1) to examine microscopic elastic and viscoelastic moduli and density variations in ultra-oriented fibers produced by flow-induced orientation and high-speed takeup; (2) to examine the interfacial regions using a non-destructive procedure in reducing the moisture absorption of epoxy resin/graphite fiber composites; (3) to characterize defects in semiconductor materials and in developing new image analysis techniques; (4) to investigate the interface during strain in polymer matrix composites (the novel utility here is due to the composites being opaque to light but still transparent to ultra- sound); (5) to assist the Precision Engineering Center (newly formed at this university) in the characterization of subsurface damage; and (6) to examine, count, and measure subsurface structures in archaeological specimens.